SW6231104_Design Calculations_20231115

TRACTOR SUPPLY STORE - WEST END
MOORE COUNTY, NC
Table of Contents
STORMWATER DESIGN NARRATIVE
STORM SEWERS DESIGN
PROPOSED EROSION CONTROL MEASURES
APPENDIX:
POND SPREADSHEET CALCULATIONS
EROSION CONTROL CALCULATIONS
RETAINING WALL MAINTENANCE
DRAINAGE AREA MAP
Page 2 of 5

STORMWATER DESIGN NARRATIVE
West End Development Group, LLC proposes to construct a retail building and accessory equipment
display areas for a Tractor Supply Store for farm and home supplies. This site is located at the
intersection of NC 211 and NC 73 in Moore County.
The property is further identified by Moore County PINs #: 00020642, 00021818, 20220140, 20220139,
that will be recombined into one parcel at the time of purchase by the applicant. The site is cleared and
wooded along the rear property line. The site topography ranges from 600 to 588 and drains to the rear
or adjacent subdivision that feeds the upstream tributary to Lower Little River (Water Supply Watershed
Class III; HQW) of the Cape Fear River. There are no surface waters or wetlands on this property.
Map unit symbol Map unit name Rating Percent of AOI
AeB Alley loamy sands B 30%
CaB Candor Sand A 50%
CbC Candor urban land A 20%
An infiltration basin is proposed at the rear of the property. The infiltration basin is designed to store the
difference in the pre and post runoff volume per the local Moore County Stormwater Rules. Storm
Routing was modeled using HydroCAD's TR-55 Software Routine. The pre-development and post-
development curve numbers calculations are included within the HydroCAD Report.
The infiltration basin stores and recharges and doesn't release any discharge for the followingdesign
storms (2-yr thru 1000-yr storm events). The following chart is a summary of pre/post discharge rates
and peak elevations:
SITE DRAINAGE AREA 2yr 10yr 25yr 100yr 500yr 1000yr
0.1 1.5 4.1 9.9 18.5 23.1
Pre-Development(cfs)
Post-Development(cfs) 0 0 0 0 0 0
2yr 10yr 25yr 100yr 500yr 1000yr
Infiltration Basin WSEL 588.33 589.89 590.72 591.90 593.20 593.77
Em. Spwy. Elevation = 594.00. All elevations provided reference NAVD88 vertical datum.
Page 3 of 5

PROPOSED EROSION CONTROL MEASURES
A. TEMPORARY CONSTRUCTION ENTRANCE. One temporary gravel construction entrance is
installed at the proposed driveway location off NC 73.
B. TEMPORARY SILT(SEDIMENT) FENCE. Temporary silt fence will be used to control sediment
runoff from fill areas and to prevent any construction sediment or trash from leaving the
property or entering wetlands or other sensitive features.
C. RIP-RAP OUTLET PROTECTION. Outlet protections are shown on the pipe outfalls into pond
and the pond outlet structure barrel pipe. The rip-rap will prevent scour and erosion from
washing bottoms and slopes of earthwork.
D. TEMPORARY INLET PROTECTION. Inlet protections are shown on the proposed inlets to
prevent sediment-runoff from clogging the storm drain inlets and pipes and reduce sediment
into the future wet pond.
E. TEMPORARY SKIMMER SEDIMENT BASIN. The stormwater pond will be used as sediment
storage device initially and converted to permitted wet pond after construction. Sediment
runoff shall be removed to establish wet pond elevations. A Skimmer 'top-water' dewatering
device' is inserted onto the pond outlet structure. Baffles are not included within the
sediment basin detail due to high groundwater negating any sediment capture effects of a
porous baffle.
F. TEMPORARY DIVERSION DITCHES WITH EXCELSIOR LINING AND WATTLES. Temporary
diversion ditches with excelsior matting are to be used to carry the areas where silt fence is
inadequate because of drainage area and the ditches discharge into a temporary sediment
basin via temporary slope drains to prevent cuts into the wet pond slopes. Excelsior wattles
or rip-rap check dams are to be spaced out according to the plans and details based on slope
and length.
PROPOSED STORMWATER RETAINING WALL MAINTENANCE
Contractors shall be responsible for periodic inspection and maintenance of all indicated
erosion control devices. In addition, inspection and any necessary maintenance will be
required immediately following any significant storm event. Any erosion control measure
that fails to function as intended shall be repaired immediately. Upon completion of
construction and the establishment of stabilized ground cover, the property owner shall be
responsible for any ongoing site maintenance.
Segmental Retaining Operations & Maintenance Owner and Contractor shall follow
manufacturer's technical specifications for Operations and Maintenance as well as the
following:
Page 4 of 5

• The area behind the wall that contains geogrid soil reinforcement fabric is the primary
structural component of the wall system. Do not, under any circumstances, excavate though,
drill through, or otherwise damage this reinforcement fabric without written approval of the
design engineer of record.
• The wall is normally constructed over a crushed stone base. No digging or excavation shall be
done within 3 feet horizontally from bottom face of wall or to such depth that would
compromise the integrity of the wall foundation.
• Do not increase the height of the existing wall as constructed with more block units without
the written approval of the design engineer of record.
• Do not add a slope or increase the steepness of a back slope beyond what was considered in
the original grading plan and wall design without written approval of the design engineer of
record.
• All structures (i.e. sidewalks, pavements, curbs, trash enclosure, utility lines, etc.) should be
designed to handle some ground movement and not be connected directly to wall units.
• Retaining walls should be inspected at least once per year. Some, but not necessarily all
items to be inspected are; erosion has not occurred along the top, ends, or bottom of wall(s),
landscaping or planting is not interfering with the wall(s) intended performance, observe and
note any unanticipated movement or deflection of the wall system and evaluated by a
qualified engineer. Additional inspection may be necessary immediately following a
catastrophic event.
Page 5 of 5

Tractor Supply Store
NC 211 and NC 73 West End, NC
Receiving Stream: UT Little River (Lower Little River), Cape Fe,
WS-III; HQW
DA 1
TOTAL DA (sf) 285,000
Onsite (sf) 237,300
Offsite (sf) 47,700
Landscape (sf) 39,080
TOTAL BUA (sf) 155,300
% Impervious 54.49%
TOTAL BUA
Building 22200
Parking Lot 84100
Concrete and Walkways 28000
ffsite Roads (NC 73 and 211) 16000
Future 5000
TOTAL BUA (sf) 155,300

Project Name: West End TSC
Client: West End Development Group pARA MOLNTE
Prepared By: JBS
Date: 8/28/23 EN GINE E R I N INC
Infiltration Basin -DA 1
Soil Type = Sandy Soils
EL.At Test Location = 597.50 HA-01 and HA-02
Depth to SHWL= 20.0 ft See ECS Test Report 33:6510-R1
SHWL= 577.50
Min. Bottom EL. = 585.00
Infiltration Rate= 2.62 in/hr
Infiltration Rate= 4.12 in/hr
Infiltration Rate Average = 3.37 in/hr
Infiltration Rate= 1.69 in/hr FofS = 2
Drainage Area = 285000 sf DA 1
BUA Area to System = 155300 sf DA 1
Impervious 54%
Runoff Coefficent(Rv) = 0.540 in/in
Required 1.5" Runoff Volume 19,253 cf 1.5"Runoff Volume
Required 1.5" Runoff Elev. 588.30 Elev.
Provided Runoff Volume = 19,927 cf SEE HYDROCAD STAGE-STORAGE TABLE
Bottom Area of Basin 2,876 sf
Elev Stage Storage Storage Drained Qdarcy Drawdown Time
ft ft cf cf cfs sec min hours days
588.3 3.30 16,529 0 0.18509 0.0 0 0 0
587.0 2.30 9,264 7,265 0.12900 56316.1 938.60 15.64 0.65
586.0 1.30 6,289 2,975 0.07292 40800.8 680.01 11.33 0.47
585.0 0.00 0
Elev Stage Storage Storage Drained Qdarcy Drawdown Time
ft ft cf cf cfs sec min hours days
594.0 9.00 97,310 0 0.50480 0.0 0 0 0
593.0 8.00 79,186 18,124 0.44871 40391.4 673.1902 11.2198 0.4675
592.0 7.00 63,151 16,035 0.39262 40841.0 680.6826 11.3447 0.4727
591.0 6.00 48,862 14,289 0.33653 42459.6 707.6594 11.7943 0.4914
590.0 5.00 36,328 12,534 0.28044 44693.5 744.8921 12.4149 0.5173
589.0 4.00 25,551 10,777 0.22435 48035.6 800.5926 13.3432 0.556
588.0 3.00 16,529 9,022 0.16827 53617.5 893.6249 14.8937 0.6206
587.0 2.00 9,264 7,265 0.11218 64763.5 1079.392 17.9899 0.7496
586.0 1.00 6,289 2,975 0.05609 53041.0 884.0171 14.7336 0.6139
585.0 0.00 0

NOAA Atlas 14,Volume 2,Version 3 SOUTHERN
PINES 2 W
'6„*� t Station ID:31-8089 „, •s,,,
if p Location name: Pinehurst, North Carolina, USA* i noon
Latitude:35.1667°,Longitude: -79.4333°
Elevation: iS)
''"`6 Elevation(station metadata):502 ft** wn,"`
*source:ESRI Maps
**source:USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M.Bonnin,D.Martin,B.Lin,T.Parzybok,M.Yekta,and D.Riley
NOAA,National Weather Service,Silver Spring,Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1
Average recurrence interval(years)
Duration
1 2 5 10 25 50 100 200 500 1000
5-min 0.441 0.521 0.605 0.667 0.739 0.789 0.836 0.878 0.928 0.966
(0.401-0.487) (0.474-0.576) (0.550-0.669) (0.605-0.735) (0.666-0.813) (0.710-0.868) (0.748-0.919) (0.782-0.966) (0.819-1.02) (0.846-1.06)
10-min 0.704 0.833 0.970 1.07 1.18 1.26 1.33 1.39 1.47 1.52
(0.641-0.777) (0.758-0.921) (0.881-1.07) (0.967-1.18) (1.06-1.30) (1.13-1.38) (1.19-1.46) (1.24-1.53) (1.30-1.62) (1.33-1.68)
15-min 0.880 1.05 1.23 1.35 1.49 1.59 1.68 1.76 1.85 1.91
(0.801-0.972) (0.953-1.16) (1.11-1.36) (1.22-1.49) 1 (1.35-1.64) (1.43-1.75) 1 (1.50-1.85) (1.56-1.93) (1.63-2.03) (1.67-2.10)
30-min 1.21 1.45 1.74 1.96 2.21 2.40 2.57 2.73 2.94 3.09
(1.10-1.33) (1.32-1.60) (1.58-1.93) (1.77-2.16) (1.99-2.43) (2.16-2.64) (2.30-2.83) (2.43-3.01) (2.59-3.24) (2.71-3.41)
60-min 1.50 1.82 2.23 2.55 2.94 3.25 3.54 3.83 4.22 4.52
(1.37-1.66) (1.65-2.01) i (2.03-2.47) I (2.31-2.81) 1 (2.65-3.24) (2.92-3.57) (3.17-3.90) (3.41-4.22) (3.72-4.64)1 (3.95-4.97)
2-hr 1.76 2.14 I 2.67 I 3.07 3.59 4.00 4.40 4.81 5.35 I 5.78
(1.60-1.97) (1.94-2.38) (2.41-2.97) (2.77-3.41) (3.22-3.99) (3.57-4.44) (3.91-4.89) (4.24-5.34) (4.67-5.94) (4.99-6.42)
3-hr 1.87 2.26 2.84 3.29 3.90 4.38 4.87 5.39 6.09 6.66
(1.69-2.08) (2.05-2.52) (2.57-3.16) (2.97-3.65) (3.50-4.32) (3.91-4.86) (4.32-5.40) (4.73-5.96) (5.29-6.75) (5.72-7.38)
6-hr 2.23 2.70 3.38 3.92 4.67 5.27 5.89 6.53 7.42 8.14
(2.03-2.47) (2.45-2.98) i (3.08-3.74) (3.55-4.33) (4.20-5.14) (4.70-5.80) I (5.21-6.47) (5.73-7.17) (6.43-8.14)1 (6.97-8.94)
12-hr 2.63 3.19 1 4.02 4.69 5.62 6.38 7.18 8.02 9.21 10.2
(2.39-2.92) (2.90-3.53) (3.64-4.45) (4.24-5.18) (5.04-6.19) (5.68-7.01) (6.33-7.87) (6.99-8.79) (7.91-10.1) (8.61-11.1)
24-hr 3.09 3.73 4.69 5.45 6.49 7.31 8.16 9.04 10.2 11.2
(2.86-3.35) (3.45-4.05) (4.34-5.09) (5.03-5.91) (5.97-7.03) (6.71-7.92) (7.47-8.84) (8.25-9.78) (9.31-11.1) (10.1-12.1)
2-day 3.60 4.33 5.41 6.27 7.43 8.35 9.29 10.3 11.6 12.6
(3.34-3.88) (4.03-4.68) I (5.03-5.85) (5.80-6.77) (6.85-8.01) (7.69-9.00) (8.54-10.0) (9.40-11.1) (10.6-12.5) (11.5-13.7)
3-day 3.82 4.59 5.70 6.58 7.78 8.74 9.72 10.7 12.1 13.2
(3.55-4.10) (4.28-4.94) (5.31-6.13) (6.12-7.07) (7.21-8.36) (8.07-9.38) (8.95-10.4) (9.84-11.5) (11.1-13.0) (12.0-14.2)
4-day 4.03 4.85 5.99 6.90 8.14 9.13 10.1 11.2 12.6 13.8
_ (3.77-4.32) (4.53-5.19) (5.59-6.40) (6.42-7.37) (7.56-8.70) (8.45-9.75)_ (9.36-10.9) (10.3-12.0) (11.6-13.5) (12.6-14.8)
7-day 4.66 5.56 6.79 7.76 9.11 10.2 1 11.3 12.4 13.9 15.2
(4.35-4.98) (5.20-5.95) (6.34-7.27) (7.23-8.31) (8.46-9.74) (9.43-10.9) (10.4-12.1) (11.4-13.3) (12.8-14.9) (13.9-16.3)
10-day 5.32 6.34 7.63 8.64 10.0 I 11.1 12.2 I 13.3 I 14.8 15.9
(5.02-5.67) (5.97-6.74) (7.18-8.11) (8.12-9.18) (9.38-10.6) (10.4-11.8) (11.3-13.0) (12.3-14.1) (13.7-15.8) (14.7-17.0)
20-day 7.17 8.47 10.0 11.2 12.9 14.2 15.5 16.8 18.6 20.0
(6.77-7.59) (8.01-8.96) (9.46-10.6) (10.6-11.9) (12.1-13.6) (13.3-15.0) (14.5-16.4) (15.7-17.8) (17.2-19.7) (18.5-21.2)
30-day 8.90 10.5 12.2 13.5 15.3 16.6 18.0 19.3 21.1 22.5
(8.42-9.41) (9.92-11.1) (11.5-12.9) (12.8-14.3) (14.4-16.2) (15.7-17.6) (16.9-19.0) (18.1-20.5) (19.7-22.4) (21.0-23.9)
45-day 11.3 13.2 15.1 16.6 18.5 20.0 21.4 22.8 24.6 26.0
(10.7-11.9)_ (12.5-14.0) (14.3-16.0) (15.7-17.5) (17.5-19.5) (18.8-21.0) (20.1-22.6) (21.4-24.0) (23.0-26.0) (24.3-27.5)
60-day 13.5 15.8 17.9 19.5 21.6 23.2 24.7 26.1 28.1 29.5
(12.8-14.2) (15.0-16.6) (17.0-18.8) i (18.5-20.5) (20.4-22.7) , (21.9-24.3) 1 (23.3-26.0) 1 (24.6-27.5) , (26.4-29.6)I (27.7-31.2)
1 Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates
(for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds
are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values.
Please refer to NOAAAtlas 14 document for more information.
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PF graphical

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Hydrologic Soil Group—Moore County, North Carolina
M
A
620350 630380 630410 630440 630470 630500 630530 630560 630590 630620 630650
35°14'30"N 1- 35°14'30'N
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630350 620380 630410 630440 630470 630500 630530 630560 630590 630620 630650
3 3
in o
A Map Scale:1:1,470 if printed on A landscape(11"x 8.5")sheet. M
Meters N
0 20 40 80 120
Feet
0 50 100 200 300
Map projection:Web Mercator Corner coordinates:WGS84 Edge tics:UTM Zone 17N WGS84
USDA Natural Resources Web Soil Survey 10/26/2023
Conservation Service National Cooperative Soil Survey Page 1 of 4

Hydrologic Soil Group—Moore County, North Carolina
MAP LEGEND MAP INFORMATION
Area of Interest(AOI) p C The soil surveys that comprise your AOI were mapped at
Area of Interest(AOI) 1:24,000.
0 C/D
Soils • D Warning:Soil Map may not be valid at this scale.
Soil Rating Polygons
l A p Not rated or not available Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
n A/D Water Features line placement.The maps do not show the small areas of
Streams and Canals contrasting soils that could have been shown at a more detailed
n B scale.
Transportation
Q B/D
r4-1. Rails Please rely on the bar scale on each map sheet for map
n C measurements.
ti Interstate Highways
C/D US Routes Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
0 D Major Roads Coordinate System: Web Mercator(EPSG:3857)
n Not rated or not available Local Roads
Maps from the Web Soil Survey are based on the Web Mercator
Soil Rating Lines Background projection,which preserves direction and shape but distorts
• • A distance and area.A projection that preserves area,such as the
1111 Aerial Photography Albers equal-area conic projection,should be used if more
• • A/D accurate calculations of distance or area are required.
^r B This product is generated from the USDA-NRCS certified data as
.v B/D of the version date(s)listed below.
• r C Soil Survey Area: Moore County,North Carolina
Survey Area Data: Version 26,Sep 13,2023
• • C/D
Soil map units are labeled(as space allows)for map scales
• • D 1:50,000 or larger.
• w Not rated or not available Date(s)aerial images were photographed: Apr 23,2022—Apr
Soil Rating Points 27,2022
p A The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
O A/D imagery displayed on these maps.As a result,some minor
• B shifting of map unit boundaries may be evident.
• B/D
USDA Natural Resources Web Soil Survey 10/26/2023
Conservation Service National Cooperative Soil Survey Page 2 of 4

Hydrologic Soil Group—Moore County, North Carolina
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
AeB Ailey loamy sand,2 to 8 B 2.3 30.0%
percent slopes
CaB Candor sand,0 to 4 A 3.6 48.1%
percent slopes
CbC Candor-Urban land A 1.6 21.8%
complex,2 to 12
percent slopes
Totals for Area of Interest 7.5 100.0%
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential)when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential)when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
USDA Natural Resources Web Soil Survey 10/26/2023
Conservation Service National Cooperative Soil Survey Page 3 of 4

Section 02834 (32 32 23)
CONCRETE RETAINING WALL
PART 1: GENERAL
1.01 Description
A.Work shall consist of designing,furnishing and construction of a Retaining Wall System in accordance with these
specifications and to the lines,grades, design, and dimensions shown on the plans. No alternate wall systems will be
considered.
B.Work includes preparing foundation soil,furnishing and installing leveling pad, unit drainage fill and backfill to the
lines and grades shown on the construction drawings.
C.Work includes furnishing and installing geogrid soil reinforcement of the type, size, location, and lengths
designated on the construction drawings.
1.02 Related Sections
A. Section 02300(31 00 00)-Earthwork
1.03 Reference Documents
A.American Society for Testing and Materials(ASTM)
1.ASTM C140 Standard Test Methods for Sampling and Testing Concrete Masonry Units and Related Units
2.ASTM C1262 Standard Test Method for Evaluating the Freeze-Thaw Durability
3.ASTM C1372 Standard Specification for Dry-Cast Segmental Retaining Wall Units
4.ASTM D422 Standard Test Method for Particle-Size Analysis of Soils
5.ASTM D698 Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort
(12,400 ft-lbf/ft3(600 kN-m/m3))
6.ASTM D1557 Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort
(56,000 ft-lbf/ft3(2,700 kN-m/m3))
7.ASTM D3034 Standard Specification for Type PSM Poly Vinyl Chloride(PVC)Sewer Pipe and Fittings
8.ASTM D4318 Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils
9.ASTM D4475 Horizontal Shear Strength of Pultruded Reinforced Plastic Rods
10.ASTM D4476 Flexural Properties of Fiber Reinforced Pultruded Plastic Rods
11.ASTM D4595 Standard Test Method for Tensile Properties of Geotextiles by the Wide-Width Strip Method
12.ASTM D5262 Standard Test Method for Evaluating the Unconfined Tension Creep and Creep Rupture Behavior
of Geosynthetics
13.ASTM D5818 Standard Practice for Exposure and Retrieval of Samples to Evaluate Installation Damage of
Geosynthetics
14.ASTM D6637 Standard Test Method for Determining Tensile Properties of Geogrids by the Single or Multi-Rib
Tensile Method
15.ASTM D6638 Standard Test Method for Determining Connection Strength Between Geosynthetic Reinforcement
and Segmental Concrete Units(Modular Concrete Blocks)
16.ASTM D6706 Standard Test Method for Measuring Geosynthetic Pullout Resistance in Soil
17.ASTM D6916 Standard Test Method for Determining the Shear Strength Between Segmental Concrete Units
(Modular Concrete Blocks)
B.American Association of State Highway and Transportation Officials (AASHTO)
1.AASHTO M252 Corrugated Polyethylene Drainage Pipe
2.AASHTO M288 Standard Specification for Geotextile Specification for Highway Applications
1.05 Quality Assurance
A. Owner shall provide soil testing and quality assurance inspection during earthwork and wall construction
operations. Contractor shall provide quality control testing and inspection during construction. Owner's quality
assurance program does not relieve the contractor of responsibility for quality control and wall performance.
1.06 Delivery, Storage and Handling

A. Contractor shall check all materials upon delivery to assure that the proper type, grade, color, and certification
have been received.
B. Contractor shall protect all materials from damage due to job site conditions and in accordance with manufacturer's
recommendations. Damaged materials shall not be incorporated into the work.
PART 2: PRODUCTS
2.02 Concrete Retaining Wall Units
B. Concrete materials shall conform to the requirements of ASTM C1372-Standard Specifications for Segmental
Retaining Wall Units.
C. Concrete units shall conform to the following structural and geometric requirements measured in accordance with
ASTM C140 Sampling and Testing Concrete Masonry Units,ASTM D6916 Determining the Shear Strength Between
Segmental Concrete Units and ASTM D6638 Determining Connection Strength Between Geosynthetic
Reinforcement and Segmental Concrete Units:
1. Compressive strength: >_3000 psi (21 MPa)
2.Absorption: <_8 %for standard weight aggregates. Note to Specifier:
Select appropriate unit(s)below and delete others.
3. Keystone Standard Units:
a.Width: 18"(457 mm).
b. Depth: 18"-21" (457-533 mm), not including rough split face.
c. Height: 8" (203 mm).
d.Weight: 82- 114 pounds(37-52 kg)per unit minimum using standard weight aggregates.
4. Keystone Compac Units:
a.Width: 18"(457 mm).
b. Depth: 12"(305 mm), not including rough split face.
c. Height: 8" (203 mm).
d.Weight:67-89 pounds(30-40 kg)per unit minimum using standard weight aggregates.
5. Keystone Century Wall Units:
a.Width:Varies—7- 18"(178-457 mm).
b. Depth: 12"(305 mm)minimum, not including rough split face.
c. Height: 8" (203 mm)and 4"(101 mm).
d.Weight:20-87 pounds(9-39 kg)per unit minimum using standard weight aggregates.
6. Keystone Country Manor Units:
a.Width:4"- 16" (101 -406 mm).
b. Depth: 10"(254 mm)minimum, not including rough split face.
c. Height: 6" (152 mm).
d.Weight:21 -65 pounds(10-29 kg)per unit minimum using standard weight aggregates.
7.Accessory Units: Provide matching units.
a. Corners: Provide 90 degree corners,finished two sides,where indicated.
b. Cap units: Provide solid cap units.
D. Keystone concrete units shall conform to the following construction
requirements:
1.Vertical setback: 1/8"(3 mm)±per course (near vertical)or 1"(25 mm)+ per course per the design;
2.Alignment and grid positioning mechanism fiberglass pins,two per unit minimum(one pin for small units).
3. Maximum horizontal gap between erected units shall be<_ 1/2"(13 mm).
2.03 Shear Connectors
A. Shear connectors shall be 1/2" (12 mm)diameter thermoset isopthalic polyester resin pultruded fiberglass
reinforcement rods to provide connection between vertically and horizontally adjacent units with the following
requirements:
1. Flexural Strength in accordance with ASTM D4476: 128,000 psi (882 MPa) minimum;

2. Short Beam Shear in accordance with ASTM D4475: 6,400 psi (44 MPa) minimum.
B. Shear connectors shall be capable of holding the geogrid in the proper design position during grid pre tensioning
and backfilling.
2.04 Base Leveling Pad Material
A. Material shall consist of a compacted crushed stone base or non-reinforced concrete as shown on the construction
drawings.
2.05 Unit Drainage Fill
A. Unit drainage fill shall consist of clean 1"(25 mm)minus crushed stone or crushed gravel meeting the following
gradation tested in accordance with ASTM D422:
Sieve Size Percent Passing
1" (25 mm) 100
3/4"(19 mm)75- 100
No.4(4.75mm)0-10
No. 50(300um)0-5
B. Drainage fill shall be placed within the cores of, between,and behind the units as indicated on the design
drawings. Not less than one cubic foot(0.028 m3), of drainage fill shall be used for each square foot(0.093 m2)of
wall face unless otherwise specified.
2.06 Reinforced Backfill
A. Reinforced backfill shall be free of debris and organic material; meeting the following gradation tested in
accordance with ASTM D422:
Sieve Size Percent Passing
3/4"(19 mm) 100-75
No.40(425um)0-60
No. 200(75um)0-35
Plasticity Index(PI)<15 and Liquid Limit(LL)<40 per ASTM D4318.
B.The maximum aggregate size shall be limited to 3/4"(19 mm)unless field tests have been performed to evaluate
potential strength reductions to the geogrid design due to damage during construction.
C. Material can be site-excavated soils where the above requirements can be met. Unsuitable soils for backfill (high
plastic clays or organic soils)shall not be used in the backfill or in the reinforced soil mass.
D. Contractor shall submit reinforced fill sample and laboratory test results to the Architect/Engineer for approval prior
to the use of any proposed reinforced fill material.
2.07 Geogrid Soil Reinforcement
A. Geosynthetic reinforcement shall consist of geogrids manufactured specifically for soil reinforcement applications
and shall be manufactured from high tenacity polyester yarn or high density polyethylene. Polyester geogrid shall be
knitted from high tenacity polyester filament yarn with a molecular weight exceeding 25,000 g/m and a carboxyl end
group values less than 30. Polyester geogrid shall be coated with an impregnated PVC coating that resists peeling,
cracking, and stripping.
B.Ta, Long Term Allowable Tensile Design Load, of the geogrid material shall be determined as follows:
Ta =Tult/(RFcr*RFd*RFid*FS)
Ta shall be evaluated based on a 75-year design life.
1.Tult, Short Term Ultimate Tensile Strength shall be determined in accordance with ASTM D4595 or ASTM D6637.
Tult is based on the minimum average roll values(MARV).
2. RFcr, Reduction Factor for Long Term Tension Creep
RFcr shall be determined from 10,000-hour creep testing performed in accordance with ASTM D5262- RFcr can
typically vary from 1.40 to 4.0.

3. RFd, Reduction Factor for Durability
RFd shall be determined from polymer specific durability testing covering the range of expected soil environments.
RFd can typically vary from 1.10 to 2.0.
4. RFid, Reduction Factor for Installation Damage
RFid shall be determined from product specific construction damage testing performed in accordance with ASTM
D5818.Test results shall be provided for each product to be used with project specific or more severe soil type. RFid
can typically vary from 1.05 to 2.0.
5. FS, Overall Design Factor of Safety
FS shall be 1.5 unless otherwise noted for the maximum allowable working stress calculation.
C. The maximum design tensile load of the geogrid shall not exceed the laboratory tested ultimate strength of the
geogrid/facing unit connection divided by a factor of safety of 1.5.The connection strength testing and computation
procedures shall be in accordance with ASTM D6638 Connection Strength between Geosynthetic Reinforcement and
Segmental Concrete Units.
D. Soil Interaction Coefficient, Ci
Ci values shall be determined per ASTM D6706 at a maximum 3/4" (19 mm)displacement.
E. Manufacturing Quality Control
The geogrid manufacturer shall have a manufacturing quality control program that includes QC testing by an
independent laboratory.
The QC testing shall include:
Tensile Strength Testing
Melt Flow Index(HDPE)
Molecular Weight(Polyester)
2.08 Drainage Pipe
A. If required,the drainage pipe shall be perforated or slotted PVC pipe manufactured in accordance with ASTM
D3034 or corrugated HDPE pipe manufactured in accordance with AASHTO M252.
2.09 Geotextile Filter Fabric
A.When required, Geotextile filter fabric shall be 4.0 oz/sy, polypropylene, needle-punched nonwoven fabric in
accordance with AASHTO M288.
PART 3: EXECUTION
3.01 Excavation
A. Contractor shall excavate to the lines and grades shown on the construction drawings. Owner's representative
shall inspect the excavation and approve the foundation soils prior to placement of leveling material or fill soils.
B. Over excavation and replacement of unsuitable foundation soils and replacement with approved compacted fill will
be compensated as agreed upon with the Owner.
3.02 Base Leveling Pad
A. Leveling pad material shall be placed to the lines and grades shown on the construction drawings,to a minimum
thickness of 6"(150 mm)and extend laterally a minimum of 6"(150 mm)in front and behind the wall unit.
B. Soil leveling pad materials shall be compacted to a minimum of 95% Standard Proctor density per ASTM D698 or
92% Modified Proctor Density per ASTM D1557.
C. Leveling pad shall be prepared to insure full contact to the base surface of the concrete units.
3.03 Unit Installation
A. First course of units shall be placed on the leveling pad at the appropriate line and grade.Alignment and level shall
be checked in all directions; insuring that all units are in full contact with the base and properly seated.

B. Place the front of units side-by-side. Do not leave gaps between adjacent units. Layout of corners and curves shall
be in accordance with manufacturer's recommendations.
C. Install shear/connecting devices per manufacturer's recommendations.
D. Place drainage fill within and behind wall units. Place and compact backfill soil behind drainage fill. Follow wall
erection and drainage fill closely with structure backfill.
E. Maximum stacked vertical height of wall units, prior to unit drainage fill and backfill placement and compaction,
shall not exceed two courses.
3.04 Structural Geogrid Installation
A. Geogrid shall be oriented with the highest strength axis perpendicular to the wall alignment.
B. Geogrid reinforcement shall be placed at the strengths, lengths, and elevations shown on the construction design
drawings or as directed by the Engineer.
C.The geogrid shall be laid horizontally on compacted backfill and attached to the Keystone wall units. Place the next
course of Keystone concrete units over the geogrid. The geogrid shall be pulled taut, and anchored prior to backfill
placement on the geogrid.
D. Geogrid reinforcements shall be continuous throughout their embedment lengths and placed side-by-side to
provide 100%coverage at each level. Spliced connections between shorter pieces of geogrid or gaps between
adjacent pieces of geogrid are not permitted.
3.05 Reinforced Backfill Placement
A. Reinforced backfill shall be placed, spread, and compacted in such a manner that minimizes the development of
slack in the geogrid and installation damage.
B. Reinforced backfill shall be placed and compacted in lifts not to exceed 6"(150 mm)where hand operated
compaction is used, or 8- 10"(200 to 250 mm)where heavy self-propelled compaction equipment is used. Lift
thickness shall be decreased to achieve the required density, as needed.
C. Reinforced backfill shall be compacted to a minimum of 95% Standard Proctor density per ASTM D698 or 92%
Modified Proctor Density per ASTM D1557.The moisture content of the backfill material prior to and during
compaction shall be uniformly distributed throughout each layer.
D. Only lightweight hand operated equipment shall be allowed within 3 feet(1 m)from the tail of the concrete unit.
E.Tracked construction equipment shall not be operated directly upon the geogrid reinforcement.A minimum fill
thickness of 6"(150 mm)is required prior to operation of tracked vehicles over the geogrid.Tracked vehicle turning
should be kept to a minimum to prevent tracks from displacing the fill and damaging the geogrid.
F.At the end of each day's operation,the Contractor shall slope the last lift of reinforced backfill away from the wall
units to direct runoff away from wall face. The Contractor shall not allow surface runoff from adjacent areas to enter
the wall construction site.
3.06 Cap Installation
A. Cap units shall be glued to underlying units with an all-weather adhesive recommended by the manufacturer.
3.07 As-built Construction Tolerances
A.Vertical alignment: ± 1.5"(40 mm)over any 10' (3 m)distance.
B.Wall Batter:within 2 degrees of design batter.
C. Horizontal alignment: ± 1.5"(40 mm)over any 10' (3 m)distance.
Corners, bends&curves: ± 1 foot(300 mm)to theoretical location.
D. Maximum horizontal gap between erected units shall be<_ 1/2"(13 mm).

3.08 Field Quality Control
A.Wall construction shall be monitored by a qualified Engineer to verify field conditions. If this work is not performed
by the site geotechnical engineer, the geotechnical engineer shall be consulted in those matters pertaining to soil
conditions and wall performance.
B.The foundation soils at each wall location shall be inspected by the Engineer and any unsuitable soils or
improperly compacted material shall be removed and replaced as directed by the Engineer pior to wall construction to
provide adequate bearing capacity and minimize settlement.
C.All wall excavation and retained soils shall be inspected for groundwater conditions and any additional drainage
provisions required in the field shall be incorporated into the wall construction as directed by the Engineer.
D.Wall backfill material shall be tested and approved by the Engineer for use in the reinforced soil zone meeting the
minimum requirements of the approved design plans.
E.All soil backfill shall be tested by the Engineer for moisture, density, and compaction periodically(every 2'
vertically, 100'-200'c/c)meeting the minimum requirements of the approved design plans or project specifications.
F.Wall construction shall be periodically inspected by the Engineer to ensure the geogrid reinforcement elevations
and lengths are installed in accordance with the approved design plans.
G.All wall elevations, grades, and backslope conditions shall be verified by the Engineer in the field for conformance
with the approved design plans. Any revisions to the structure geometry or design criteria shall require design
modification prior to proceeding with construction.

FINISH GRADE
CAP UNIT
SLOPE VARIES
—0— \•
} GEOGRID
w
U
p I
w \
° ' REINFORCED I RETAINED
SEGMENTAL WALL UNIT w BACKFILL BACKFILL
FINISH GRADE \ . .
a
UNIT CORE FILL
4" 0 PERF. PIPE AT 2% GRADE
VARIES__--�----------�
SLOPE
LEVELING PAD APPROX. EXCAVATION LINE
NOTES:
• INSTALL GEOGRID IN TENSION
• COMPACT SOILS TO 95% STANDARD PROCTOR
• COMPACT SOILS IN FRONT OF WALL
• STABLE FOUNDATION SHALL BE APPROVED BY A GEOTECHNICAL ENGINEER
• STRUCTURAL DESIGN OF SHOP DRAWINGS TO BE PROVIDED BY STRUCTURAL ENGINEER.
RETAINING WALL CROSS-SECTION SCHEMATIC
SCALE: NTS

DESIGN OF RIPRAP OUTLET PROTECTION
User Input Data
Calculated Value
Reference Data
Designed By: JBS Date: 10/25/23
Checked By: JBS
Company: PEI
Project Name: TSC WEST END
Project No.: 23170.PE
Site Location(City/Town) POND OUT
Culvert Id. 24"HW 100
Total Drainage Area(acres) 2.70
Step 1. Determine the tailwater depth from channel characteristics below the
pipe outlet for the design capacity of the pipe. If the tailwater depth is less
than half the outlet pipe diameter,it is classified minimum tailwater condition.
If it is greater than half the pipe diameter,it is classified maximum condition.
Pipes that outlet onto wide flat areas with no defined channel are assumed
to have a minimum tailwater condition unless reliable flood stage elevations
show otherwise.
Outlet pipe diameter,Do(in.) 24
Tailwater depth(in.) 0
Minimum/Maximum tailwater? Min TW(Fig.8.06a)
Discharge(cfs) 10.91 25-yr
Velocity(ft./s) 3.50
Step 2. Based on the tailwater conditions determined in step 1,enter Figure
8.06a or Figure 8.066,and determine dsu riprap size and minimum apron length
(L.). The ds°size is the median stone size in a well-graded riprap apron.
Step 3. Determine apron width at the pipe outlet,the apron shape,and the
apron width at the outlet end from the same figure used in Step 2.
Minimum TW Maximum TW
Figure 8.06a Figure 8.06b
Riprap d50,(ft.) 0.5 6 0 IN
Minimum apron length,La(ft.) 8
Apron width at pipe outlet(ft.) 6
Apron shape Flare
Apron width at outlet end(ft.) 10
Step 4. Determine the maximum stone diameter:
d =1.5xdso
Minimum TW Maximum TW
Max Stone Diameter,dmax(ft.) 0.75 0 9 0 IN
Step 5. Determne the apron thickness:
Apron thickness=1.5 x dmu
Minimum TW Maximum TW
Apron Thickness(ft.) 1.125 0 13.5 0 IN
Step 6. Fit the riprap apron to the site by making it level for the minimum
length,L from Figure 8.06a or Figure 8.06b. Extend the apron farther
downstream and along channel banks until stability is assured. Keep the
apron as straight as possible and align it with the flow of the receiving stream.
Make any necessary alignment bends near the pipe outlet so that the entrance
into the receiving stream is straight.
Some locations may require lining of the entire channel cross section to assure
stability.
It may be necessary to increase the size of riprap where protection of the
channel side slopes is necessary(Appendix 8.05). Where overfalls exist at
pipe outlets or flows are excessive,a plunge pool should be considered,see
page 8.06.8.

DESIGN OF RIPRAP OUTLET PROTECTION
User Input Data
Calculated Value
Reference Data
Designed By: JBS Date: 10/25/23
Checked By: JBS
Company: PEI
Project Name: TSC WEST END
Project No.: 23170.PE
Site Location(City/Town) POND OUT
Culvert Id. 24"HW 200
Total Drainage Area(acres) 3.10
Step 1. Determine the tailwater depth from channel characteristics below the
pipe outlet for the design capacity of the pipe. If the tailwater depth is less
than half the outlet pipe diameter,it is classified minimum tailwater condition.
If it is greater than half the pipe diameter,it is classified maximum condition.
Pipes that outlet onto wide flat areas with no defined channel are assumed
to have a minimum tailwater condition unless reliable flood stage elevations
show otherwise.
Outlet pipe diameter,Do(in.) 24
Tailwater depth(in.) 0
Minimum/Maximum tailwater? Min TW(Fig.8.06a)
Discharge(cfs) 13.50 25-yr
Velocity(ft./s) 4.30
Step 2. Based on the tailwater conditions determined in step 1,enter Figure
8.06a or Figure 8.06b,and determine dsu riprap size and minimum apron length
(L.). The dso size is the median stone size in a well-graded riprap apron.
Step 3. Determine apron width at the pipe outlet,the apron shape,and the
apron width at the outlet end from the same figure used in Step 2.
Minimum TW Maximum TW
Figure 8.06a Figure 8.06b
Riprap d50,(ft.) 0.5 6 0 IN
Minimum apron length,La(ft.) 10
Apron width at pipe outlet(ft.) 6
Apron shape Flare
Apron width at outlet end(ft.) 12
Step 4. Determine the maximum stone diameter:
d =1.5xdso
Minimum TW Maximum TW
Max Stone Diameter,dmax(ft.) 0.75 0 9 0 IN
Step 5. Determne the apron thickness:
Apron thickness=1.5 x dmu
Minimum TW Maximum TW
Apron Thickness(ft.) 1.125 0 13.5 0 IN
Step 6. Fit the riprap apron to the site by making it level for the minimum
length,L from Figure 8.06a or Figure 8.06b. Extend the apron farther
downstream and along channel banks until stability is assured. Keep the
apron as straight as possible and align it with the flow of the receiving stream.
Make any necessary alignment bends near the pipe outlet so that the entrance
into the receiving stream is straight.
Some locations may require lining of the entire channel cross section to assure
stability.
It may be necessary to increase the size of riprap where protection of the
channel side slopes is necessary(Appendix 8.05). Where overfalls exist at
pipe outlets or flows are excessive,a plunge pool should be considered,see
page 8.06.8.

Figure 8.O6a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<0.5 diameter)
3 o I
Outlet W• Do + La Return to Main Worksheet
pipe
diameter(to) 1
80 --- --
La —.1—rinicili ✓
T igater.0.5D. I I I t '1I' // f
0\� 60 I ii^ .Y , _
Vgt`�� i•{I 1 "
I
` .��R
prF�'� 54 f:� 1
,. , 'lI;1111■Illli liu 1111111 ( ■. 4
412 I ij!RI'
' 4 '���tl�pl_� i[Ii_NI i „rjI ■ UNN3C 'SIPALM
.w ■ 1 I, Jrl1.I11!IiLJii■. it 11�==11 ul. i i 11Pti N�
� ! ./ ■ a i 1 111u1. u � III•
u.�� i- rr° uliiiil!a fir■emm ` I ■
zo ---,slim u... .:1 �I;s9�li�I�;C�,..... _ 1 �111.111111 IIi1f11�,1r1401�r1Ji,
az.n - r,r .NN n 1 uun .n1■ v� ..
1D Emily �.oi�6 iliiiil�I l ii�ii,,,'�� 4111i .111 � 7 ',. w _
..■■ ..�IIY I II ■��IIXI I 5. 1.
_= le■.■■■111 I` f ili�iuii 3Il llu 11 ii b i' air z
Itllltf�I■ .■: I f I• a m
0' tt li ,'881 -- 11MMi i ■2to.■.fir' 'I'■ i'''
I - �! �.` I ' 11.-� �—� eN; 10.5E450•j ■u
r\{I0�0©■lla�� If ■i V1s II` � r .V.aI .0� /r'% U N n
�io1!1111 : : ,i ; egg i l II! i'iii;',
�l � 5
.� ..=lo a1
o
3 5 10 20 50 100 200 500 1000
Discharge(ft3/sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full,minimum tailwater condition(T,.c 0.5 diameter).
Rev.12)93 8.06.3

11
Post Dev DA- 1
5P
Dry Basin - Infiltration
Subcat Reach Pon Link Routing Diagram for West End TSC
Prepared by Paramounte Engineering
HydroCAD®10.10-5a s/n 08877 ©2020 HydroCAD Software Solutions LLC

11
Post Dev DA- 1
5P
Dry Basin - Infiltration
Subcat Reach Pon Link Routing Diagram for West End TSC
Prepared by Paramounte Engineering
HydroCAD®10.10-5a s/n 08877 ©2020 HydroCAD Software Solutions LLC

West End TSC
Prepared by Paramounte Engineering
HydroCAD® 10.10-5a s/n 08877 ©2020 HydroCAD Software Solutions LLC Page 2
Rainfall Events Listing (selected events)
Event# Event Storm Type Curve Mode Duration B/B Depth AMC
Name (hours) (inches)
1 1-Year NOAA 24-hr C Default 24.00 1 3.09 2

West End TSC NOAA 24-hr C 1-Year Rainfall=3.09"
Prepared by Paramounte Engineering
HydroCAD® 10.10-5a s/n 08877 ©2020 HydroCAD Software Solutions LLC Page 3
Summary for Subcatchment 2S: Post Dev DA-1
Runoff = 10.14 cfs @ 12.12 hrs, Volume= 0.646 af, Depth> 1.74"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-24.00 hrs, dt= 0.05 hrs
NOAA 24-hr C 1-Year Rainfall=3.09"
Area (sf) CN Description
155,300 98 bua
39,080 39 >75% Grass cover, Good, HSG A
194,380 86 Weighted Average
39,080 20.10% Pervious Area
155,300 79.90% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 2S: Post Dev DA-1
Hydrograph
11 I I I
10.14 cfs i I I I I I -Runoff
10— I - 4 4 4- 1 1 I
1 1 1 1 I 1 1 I NOAA 124-h r IC
9— - I- -I- -1 - H - H - H - i- - I- -I- -I- H - H - H - H - 1- -I- -I - -
1 1 1 1 I 11-Year Rainfall=3.09"
8- -1 7 T T
1 1 1 1 RunoffT Area=1194,3$0 ‘f
7—
F - ROno f VolOm;e=0.646 Of
6=
3 = 1 1 1 1 1 Runoff Depth>1 .74"
LL 5—
1 1 1 1 1 Tc=15.01 min
CM=66
2—
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

West End TSC NOAA 24-hr C 1-Year Rainfall=3.09"
Prepared by Paramounte Engineering
HydroCAD® 10.10-5a s/n 08877 ©2020 HydroCAD Software Solutions LLC Page 4
Summary for Pond 5P: Dry Basin - Infiltration
Inflow Area = 4.462 ac, 79.90% Impervious, Inflow Depth > 1.74" for 1-Year event
Inflow = 10.14 cfs @ 12.12 hrs, Volume= 0.646 of
Outflow = 0.70 cfs @ 13.42 hrs, Volume= 0.581 af, Atten= 93%, Lag= 78.0 min
Discarded = 0.70 cfs @ 13.42 hrs, Volume= 0.581 af
Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af
Routing by Stor-Ind method, Time Span= 5.00-24.00 hrs, dt= 0.05 hrs
Peak Elev= 587.68' @ 13.42 hrs Surf.Area= 7,577 sf Storage= 13,994 cf
Plug-Flow detention time= 235.5 min calculated for 0.579 af(90% of inflow)
Center-of-Mass det. time= 184.8 min ( 1,010.5 - 825.7 )
Volume Invert Avail.Storage Storage Description
#1 585.00' 139,639 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
585.00 585.00 2,876 0 0
593.00 16,923 79,196 79,196
594.00 19,304 18,114 97,310
595.00 21,785 20,545 117,854
596.00 21,785 21,785 139,639
Device Routing Invert Outlet Devices
#1 Discarded 585.00' 3.000 in/hr Exfiltration over Surface area
Conductivity to Groundwater Elevation = 580.00'
#2 Primary 594.00' 25.0' long x 10.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Discarded OutFlow Max=0.70 cfs @ 13.42 hrs HW=587.68' (Free Discharge)
L1=Exfiltration ( Controls 0.70 cfs)
Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=585.00' (Free Discharge)
4-2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

West End TSC NOAA 24-hr C 1-Year Rainfall=3.09"
Prepared by Paramounte Engineering
HydroCAD® 10.10-5a s/n 08877 ©2020 HydroCAD Software Solutions LLC Page 5
Pond 5P: Dry Basin - Infiltration
Hydrograph
11 - - -
10.14 cfs 1 1 -Inflow
10 i I- -I - - - - I- -I- - -Outflow
-Discarded
I I I I I Inflow Area=4.462 at -Primary
9— I - -t + I- I I -t + + 1 I 1 - + I 1 H -
I I I I I 11 Peak EIeV=9871.68'
8- I -I + f 1 F T 7 1 I 7 T I -I -
7_
I1tori-g- =1 3,99�4 of
6- I I I I I I I 1 I 1 I
3 _ I I I I I I I 1 I 1 I
i—
°° 5 I - ---1 + L- - 1- - -1 - F 1- I 7 F I 1 -I -
4- I -t t fi 1 I -fi 1 -
3- 1 1 1 1
2 I I 1 1
1 1 0.70 cfs I 1 1
10.00 cfs I 1 I f
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

West End TSC NOAA 24-hr C 1-Year Rainfall=3.09"
Prepared by Paramounte Engineering
HydroCAD® 10.10-5a s/n 08877 ©2020 HydroCAD Software Solutions LLC Page 6
Stage-Discharge for Pond 5P: Dry Basin - Infiltration
Elevation Discharge Discarded Primary Elevation Discharge Discarded Primary
(feet) (cfs) (cfs) (cfs) (feet) (cfs) (cfs) (cfs)
585.00 0.00 0.00 0.00 595.40 113.34 2.77 110.57
585.20 0.23 0.23 0.00 595.60 136.38 2.80 133.57
585.40 0.27 0.27 0.00 595.80 162.23 2.84 159.39
585.60 0.30 0.30 0.00 596.00 189.55 2.87 186.68
585.80 0.34 0.34 0.00
586.00 0.37 0.37 0.00
586.20 0.41 0.41 0.00
586.40 0.45 0.45 0.00
586.60 0.48 0.48 0.00
586.80 0.52 0.52 0.00
587.00 0.56 0.56 0.00
587.20 0.60 0.60 0.00
587.40 0.65 0.65 0.00
587.60 0.69 0.69 0.00
587.80 0.73 0.73 0.00
588.00 0.77 0.77 0.00
588.20 0.82 0.82 0.00
588.40 0.86 0.86 0.00
588.60 0.91 0.91 0.00
588.80 0.95 0.95 0.00
589.00 1.00 1.00 0.00
589.20 1.05 1.05 0.00
589.40 1.09 1.09 0.00
589.60 1.14 1.14 0.00
589.80 1.19 1.19 0.00
590.00 1.24 1.24 0.00
590.20 1.29 1.29 0.00
590.40 1.34 1.34 0.00
590.60 1.39 1.39 0.00
590.80 1.44 1.44 0.00
591.00 1.49 1.49 0.00
591.20 1.54 1.54 0.00
591.40 1.59 1.59 0.00
591.60 1.64 1.64 0.00
591.80 1.70 1.70 0.00
592.00 1.75 1.75 0.00
592.20 1.80 1.80 0.00
592.40 1.86 1.86 0.00
592.60 1.91 1.91 0.00
592.80 1.97 1.97 0.00
593.00 2.02 2.02 0.00
593.20 2.09 2.09 0.00
593.40 2.15 2.15 0.00
593.60 2.22 2.22 0.00
593.80 2.28 2.28 0.00
594.00 2.35 2.35 0.00
594.20 7.99 2.42 5.57
594.40 18.68 2.49 16.19
594.60 33.93 2.56 31.37
594.80 50.75 2.63 48.12
595.00 69.70 2.70 67.00
595.20 91.13 2.73 88.40

West End TSC NOAA 24-hr C 1-Year Rainfall=3.09"
Prepared by Paramounte Engineering
HydroCAD® 10.10-5a s/n 08877 ©2020 HydroCAD Software Solutions LLC
Subcatchment 12S: Pre Dev DA-1
Hydrograph
I I I I I I I I i 1 I I 1 1 I I 1
0.015* I I I I I I I I I I 1 I I 1 1 I I 1 ■Runoff
1 1 I I I I I 1 1 1 1 I I o.oi cis I
0.014' ]— NOAA 24-hr-C -1 - — t — I— -1 - — t — H —1— —1 —
0.013� J- 1 _ L _ I_ _I _ L _ 1 _ I_ _I_ _ 1 _ L _ 1_ _
0.012* 1 1rYear atnfa1I-3.d7 1 1 1 1 1 1
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Run1of Volume=9-O63-a#
0.009- jp1_ I ,,1 L 1_ ,, L _ I_ _I _ _I / L _I_ _I _ 1 _ L _ I_ _
0.008* �unoTT1_E�p 1> _ ._ 11'� 1 1 1 1 ��� 1 1 1 1 1 1
- 0.007� _
° I I I I I I I % I I I I I I
�I— �' 1 1 1 1 � 1 1 1
0.006 � eIN=4-3+ t 1 1 + + . — + -1 I — + - 1— — I
0.0053/ J_ _1_ _I _ L _ L _ I_ _I _ L _ _L _ 1_ _ _ L _I_ _I _ 1 _ L _ 1_ _
0.004* 1 1 1 1 1 1 1 1 1 1 1 1 1
0.003H I II I I I I I I I I I I 1 1 I I 1
'L 7 I 7 T I�
_ , 7 T L 1 I T L I
0.002 1 — —1 — 1 r — 1 —I— —I — + — I— — I— —
0.001* 1 1 1 1 1 1 1
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)